WO2019053964A1

WO2019053964A1 - Ink composition and printed matter

Info

Publication number: WO2019053964A1
Application number: PCT/JP2018/021245
Authority: WO
Inventors: 祐子青山; 佐藤　潤; 史泰村上; 政人岡田; 吉原　俊夫; 長谷川　靖哉; 中西　貴之
Original assignee: 大日本印刷株式会社
Priority date: 2017-09-15
Filing date: 2018-06-01
Publication date: 2019-03-21
Also published as: JPWO2019053964A1; JP7156289B2

Abstract

Provided is an ink composition containing: a rare earth complex containing one trivalent rare earth ion selected from the group consisting of Eu3+, Tb3+, Sm3+, Yb3+, Nd3+, Er3+, Pr3+, Ho3+, Tm3+, Dy3+, Ce3+, and Gd3+ and at least one organic ligand selected from a β-diketone ligand, a carboxylic acid ligand, a phosphine oxide ligand, and a nitrogen-containing aromatic heterocyclic ligand; and a long-afterglow luminescent material having an afterglow time of 1 second or more after excitation light irradiation is stopped.

Description

Ink composition and printed matter

Embodiments of the present disclosure relate to an ink composition and a printed material using the same.

There is known a printed matter requiring security, such as a lottery ticket, a gift certificate, a passing ticket, a ticket or other securities, on which an information pattern composed of numbers, characters, figures, symbols, patterns, etc. is printed.

With such printed matter, the damage caused by theft or fraudulent act of copying the printed matter with a copying machine (copier) has become a social problem, and the development of a forgery prevention technology capable of high-level authenticity judgment is urgently needed. There is.

For example, Patent Document 1 discloses a forgery-preventing printed matter using a hologram as a forgery-preventing measure for such a printed matter, but the technique using the hologram has a high manufacturing cost, so a printed matter with a low unit price is used. It is unsuitable for use.

In addition, Patent Document 2 discloses a forgery-proof certificate on which printing of a fluorescent ink that emits fluorescence with light of a certain wavelength other than visible light is invisible in the visible light region. So-called security markings, in which such specific light emitters are compounded, are always colorless and transparent, but emit light by being irradiated with light of a specific wavelength such as ultraviolet light, which makes it possible to determine authenticity. Yes, it is possible to prevent forgery without impairing the appearance and design of the printed matter.

However, with the technology described in Patent Document 2, the forgery preventing effect can not be sufficiently obtained as the forgery technology advances. Therefore, there is a need for the development of a technology that can obtain a higher forgery prevention effect.

Further, in Patent Document 3, the afterglow color after stopping the excitation light of the afterglow light emitting composition composed of the light emitting body X which is a phosphor and the light emitting body Y which is a phosphor is at the time of exciting light irradiation. Patent Document 1 discloses a technology for discriminating by visual observation that the light emission color is different from that in the above.

Japanese Patent Laid-Open No. 6-278396 Japanese Patent Application Publication No. 06-297888 Patent 5610121 gazette

However, in the afterglow light emitting composition disclosed in Patent Document 3, since the afterglow time of the phosphor is as short as less than 1 second, it is practically possible to discriminate the color change during the excitation light irradiation and after the excitation light irradiation. It was difficult to
An embodiment of the present disclosure is made in view of the above problems, and is formed using an ink composition which is excellent in emission intensity, has a large color change during and after excitation light irradiation, and is excellent in discrimination. To provide printed materials.

One embodiment of the present disclosure is selected from the group consisting of Eu3 ⁺ , Tb3 ⁺ , Sm3 ⁺ , Yb3 ⁺ , Nd3 ⁺ , Er3 ⁺ , Pr3 ⁺ , Ho3 ⁺ , Tm3 ⁺ , Dy3 ⁺ , Ce3 ⁺ , and Gd3 ^+. One trivalent rare earth ion, and at least one organic ligand selected from β-diketone ligands, carboxylic acid ligands, phosphine oxide ligands, and nitrogen-containing aromatic heterocyclic ligands And a long afterglow light emitting material whose afterglow time after excitation light irradiation is stopped is 1 second or more.

In one embodiment of the present disclosure, there is provided an ink composition, wherein the long afterglow light emitting material contains an alkaline earth metal aluminate.

In one embodiment of the present disclosure, the rare earth complex provides an ink composition including, as the organic ligand, a phosphine oxide ligand represented by the following general formula (1).

[In general formula (1), Ar ¹ and Ar ² are each independently a monovalent aromatic group which may have a substituent. In General Formula (1), Ar ³ is a divalent group represented by the following General Formula (2a), (2b) or (2c), and n is 1 or 2.

(In the general formulas (2a) to (2c), R ¹ is each independently a monovalent substituent, X is a sulfur atom or an oxygen atom, and R ² is a hydrogen atom or a hydrocarbon group, m is an integer from 0 to a substitutable site in the ring to which R ¹ is attached When R is an integer of 2 or more, R ¹ may be identical to or different from each other. )
In the general formula (1), E is a hydrogen atom or a phosphine oxide group represented by the following general formula (3).

(In General Formula (3), Ar ⁴ and Ar ⁵ are each independently a monovalent aromatic group which may have a substituent.)]

In one embodiment of the present disclosure, the rare earth complex includes a phosphine oxide bidentate ligand, and the phosphine oxide bidentate ligand forms a crosslinked structure formed by coordinating to the two rare earth ions. And providing an ink composition.

In one embodiment of the present disclosure, the rare earth complex provides an ink composition including, as the organic ligand, a β-diketone ligand represented by the following general formula (4).

(In General Formula (4), Q ¹ and Q ² are each independently a hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, Z is a hydrogen atom or a deuterium atom)

In one embodiment of the present disclosure, the long decay light emitting material is selected from the group consisting of SrAl ₂ O ₄ : Eu, Dy, Sr ₄ Al ₁₄ O ₂₅ : Eu, Dy, and CaAl ₂ O ₄ : Eu, Nd. Provided is an ink composition containing at least one selected.

One embodiment of the present disclosure provides a print having an ink layer containing a solidified product of the above-described ink composition.

An embodiment of the present disclosure can provide an ink composition excellent in emission intensity, having a large color change during or after irradiation with excitation light, and excellent in discrimination, and a printed material formed using the ink composition.

FIG. 1 is a schematic cross-sectional view showing an example of a printed matter according to an embodiment of the present disclosure. It is a figure which shows the emission spectrum immediately after UV irradiation of the ink layer which concerns on Example 2. FIG. It is a figure which shows the emission spectrum after 5 seconds of UV irradiation of the ink layer which concerns on Example 2. FIG. It is a figure which shows the emission spectrum after UV irradiation stop of the ink layer which concerns on Example 2. FIG. It is a figure which shows the emission spectrum of the ink layer which concerns on the comparative example 3 immediately after UV irradiation. It is a figure which shows the emission spectrum after 5 seconds of UV irradiation of the ink layer which concerns on the comparative example 3. FIG. It is a figure which shows the emission spectrum after UV irradiation stop of the ink layer which concerns on the comparative example 3. FIG.

Hereinafter, embodiments of the present disclosure, examples, and the like will be described with reference to the drawings and the like. However, the present disclosure can be implemented in many different modes, and is not interpreted as being limited to the description contents of the embodiments and the examples illustrated below. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, etc. of each portion in comparison with the actual embodiment in order to clarify the description, but this is merely an example, and the interpretation of the present disclosure It is not limited. In the specification and the drawings, the same elements as those described above with reference to the drawings already described may be denoted by the same reference numerals, and the detailed description may be appropriately omitted. Moreover, although it may be demonstrated using the words "upper" or "lower" for convenience of explanation, the vertical direction may be reversed.
In the present specification, when there is a certain configuration such as a certain member or a certain region “above (or below)” another configuration such as another member or another region, unless there is a particular limitation, This includes not only directly above (or just below) other configurations, but also above (or below) other configurations, ie, other configurations between (or below) other configurations. Also includes the case where the element is included.
Hereinafter, the ink composition and printed matter according to the present disclosure will be described in order.

[Ink composition]
The ink composition according to one embodiment of the present disclosure is composed of Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Yb ³⁺ , Nd ³⁺ , Er ³⁺ , Pr ³⁺ , Ho ³⁺ , Tm ³⁺ , Dy ³⁺ , Ce ³⁺ , and Gd ^3+. And at least one organic group selected from β-diketone ligands, carboxylic acid ligands, phosphine oxide ligands, and nitrogen-containing aromatic heterocyclic ligands An ink composition comprising: a rare earth complex containing a ligand; and a long afterglow light emitting material having an afterglow time after the termination of excitation light irradiation of 1 second or more.

In the present disclosure, the afterglow material refers to a material that is excited by light stimulation by irradiation with excitation light, converts energy and emits light, and continues to emit light for a predetermined time after the excitation light irradiation is stopped. In the present specification, among the afterglow materials, those having an afterglow time of less than 1 second after stopping excitation light irradiation are referred to as short afterglow light emitting materials, and those after 1 second or longer after stopping the excitation light irradiation. A material having a light time is referred to as a long persistence light emitting material.

In the present disclosure, afterglow time refers to an excitation light irradiation stop time point as 0 second, and refers to an elapsed time from this time point until light emission is not detected. In the present disclosure, the above-mentioned elapsed time measured by the following means is defined as afterglow time. The excitation light with a wavelength of 365 nm is irradiated for a predetermined time using a spectrofluorimeter (for example, FP-6600 manufactured by Nippon Bunko), and the maximum emission peak wavelength of the obtained emission spectrum is used as a detection wavelength. The point at which the shutter is closed is taken as 0 second, and the time until the emission intensity of the detection wavelength becomes 0.01% or less of the intensity value at the excitation light stop point from this point is taken as the afterglow time.

In the present disclosure, as excitation light, electromagnetic waves other than visible light can be mentioned, and for example, ultraviolet rays, infrared rays and the like can be mentioned.

The ink composition according to the present disclosure uses a combination of a rare earth complex containing a trivalent rare earth ion and the above-described organic ligand and a long afterglow light emitting material to achieve high emission intensity by irradiation with excitation light. In addition, during or after the irradiation with the excitation light, the color change is large and the discrimination is excellent.

It is estimated as follows as an effect | action in which the ink composition which concerns on this indication exhibits the above effects.
The long afterglow light-emitting material contained in the ink composition according to the present disclosure requires a certain period of time until the emission intensity is saturated due to its characteristics. For this reason, the difference in intensity between the emission intensity of the specific rare earth complex that emits light in a predetermined wavelength range and the emission intensity of the long afterglow light emitting material that emits light in a different wavelength range is It changes with the elapse of a fixed time after light irradiation. In addition, the long afterglow light emitting material contained in the ink composition according to the present disclosure has an afterglow time of 1 second or more after the excitation light irradiation is stopped. Therefore, after the excitation light irradiation is stopped, the difference between the emission intensity of the rare earth complex emitting in a predetermined wavelength range and the emission intensity of the long afterglow emitting material emitting in a wavelength range different from this is further expanded. . In addition, since the long decay light emitting material has an afterglow time of 1 second or more after the excitation light irradiation is stopped, the time for confirming the difference in emission intensity can be sufficiently secured even after the excitation light irradiation is stopped. it can. From the above, the ink composition according to the present disclosure has a large color change and is excellent in discrimination.
In the present disclosure, the color change during or after the irradiation of the excitation light may change the intensity difference of light emission observed in a plurality of wavelength regions during or after the irradiation of the excitation light. The wavelength of the luminescent color may not necessarily be the wavelength of the visible light region, and may be the wavelength corresponding to the near infrared region or the near ultraviolet region. For example, when the wavelength of the emission color to be intensified includes a wavelength corresponding to the near infrared region or the near ultraviolet region, a detector capable of detecting light in the wavelength region can be used as appropriate. When light emission in a plurality of wavelength regions is in the visible region, it is possible to visually check the change in the difference in light emission intensity as a color change during excitation light irradiation or after irradiation is stopped.

In addition, the luminous body using the specific rare earth complex has a high absorption efficiency of excitation light by the organic ligand, and can efficiently utilize the excitation light, and therefore has a high emission intensity as compared with the inorganic luminous body. Therefore, the ink composition of the present disclosure has a large color change during and after excitation light irradiation, and is excellent in discrimination. Furthermore, the light emitter using the specific rare earth complex is excellent in solubility in an organic solvent or dispersibility in a medium, and compatibility with a resin, so that it is easy to prepare a desired ink composition, which is desirable. There is also an advantage that it is easy to form an ink layer and easy to apply to various security markings.

Furthermore, the inventors of the present invention can also change the color during excitation light irradiation by rubbing the ink layer containing the solidified product of the ink composition of the present disclosure with the excitation light to generate frictional heat. It turned out that it became large and it was excellent in distinction.
In the long afterglow light emitting material contained in the ink composition of the present disclosure, carriers such as electrons and holes generated by irradiation with excitation light are temporarily trapped in capture centers, and gradually released by thermal energy at room temperature to emit light. The light emission is shown by moving to the center. Therefore, when the room temperature is instantaneously changed from room temperature by friction etc. while irradiating the excitation light, the trapped carriers are rapidly released and move to the light emission center to emit light strongly for a moment, and energy is released at this time. The light emission of the long decay light emitting material disappears. Therefore, when the ink layer containing the solidified product of the ink composition of the present disclosure is rubbed while being irradiated with excitation light to generate frictional heat, the luminescence intensity of luminescence due to the rare earth complex and the long afterglow luminescence The difference in intensity between the light emission and the light emission from the material changes.
Since the ink composition of the present disclosure uses the long afterglow light emitting material in combination with the above-described rare earth complex having high light emission intensity, the long afterglow light emitting material temporarily emits strong light and is then quenched by heating by friction or the like. In this case, a large difference in emission intensity can be obtained between the emission due to the rare earth complex and the emission due to the long afterglow light emitting material, and excellent discrimination can be obtained.
Further, since the ink composition of the present disclosure uses the long afterglow light emitting material in combination with the above-described rare earth complex having high light emission intensity, the light emission due to the rare earth complex and the light emission due to the long afterglow light emitting material Are all in the visible region, and when changes in the intensity difference of the light emission intensity can be visually confirmed as a color change, when the long decay light emitting material emits light and then is quenched by heating by friction etc. In addition, high intensity light emission due to the rare earth complex can be easily confirmed visually, and excellent discrimination can be obtained.

The ink composition of the present disclosure contains the above-mentioned specific rare earth complex and a long afterglow light emitting material, and may contain other components as needed, as long as the effects are not impaired. is there.
Hereinafter, each component of such an ink composition is demonstrated in detail in order.

<Rare earth complex>
(Rare earth ion)
As trivalent rare earth ions contained in the rare earth complex, Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Yb ³⁺ , Nd ³⁺ , Er ³⁺ , Pr ³⁺ , Ho ³⁺ , Tm ³⁺ , Dy ³⁺ , Ce ³⁺ , and Gd ³⁺ Are selected from the group consisting of Among these, from the viewpoint of obtaining high emission intensity, the rare earth complex is preferably a kind selected from the group consisting of Eu ³⁺ , Tb ³⁺ and Sm ³⁺ .

(Organic ligand)
As a ligand coordinated to a trivalent rare earth ion, at least one selected from β-diketone ligands, carboxylic acid ligands, phosphine oxide ligands, and nitrogen-containing aromatic heterocyclic ligands Containing organic ligands.

In general, excitation light absorbed by the rare earth complex is transferred from the ligand to the rare earth ion and converted to energy of light to be emitted. When the rare earth complex contains the above-mentioned organic ligand, the light energy of the excitation light absorbed by the rare earth complex can be efficiently supplied to the rare earth ion, and the energy of the supplied light in the rare earth ion Can be converted to the energy of light to be emitted with high efficiency.
As the ligand to be coordinated to the trivalent rare earth ion, a β-diketone ligand, a carboxylic acid ligand, a phosphine oxide ligand, and a nitrogen-containing aromatic, as long as the effects of the present disclosure are not impaired. At least one organic ligand selected from heterocyclic ligands may contain a different ligand.

The organic ligand preferably contains an anionic ligand in view of the stability of the complex, and preferably contains at least one of a β-diketone ligand and a carboxylic acid ligand. Among them, the β-diketone ligand is preferable because the energy of the excitation light can be efficiently supplied to the coordinated rare earth ion and the emission intensity becomes high because the absorption coefficient is high.

The organic ligand preferably contains at least one of a nitrogen-containing aromatic heterocyclic ligand and a phosphine oxide ligand, which are neutral ligands, from the viewpoint of enhancing the emission intensity. Since the nitrogen-containing aromatic heterocyclic ligand has a high absorption coefficient, it can efficiently supply the energy of excitation light to the coordinated rare earth ion, and the emission intensity is improved. In addition, since the phosphine oxide ligand contains a low vibration P = O skeleton, it functions so as not to cause vibrational deactivation of the energy received by the coordinated rare earth ion. When the low vibration frame is included, heat inactivation at the time of conversion of light energy is suppressed, so that the light emission efficiency is enhanced and the light emission intensity is improved.

In addition, since a carbon atom substituted with a halogen atom such as a C—X (X is a halogen atom: F, Cl, Br and I) bond has a low vibration skeleton (C—X bond), Similarly, the light emission efficiency is improved, and the light emission intensity is improved. As a low vibration frame, for example, a perhalogenated alkyl group can be mentioned, and a trifluoromethyl group can be mentioned as a specific example.

From the above, as the organic ligand, at least one anionic ligand of β-diketone ligand and carboxylic acid ligand, phosphine oxide ligand and nitrogen-containing aromatic heterocyclic ring coordination It is preferable to include at least one kind of at least one kind of at least one anionic ligand of a β-diketone ligand, at least one of a phosphine oxide ligand and a nitrogen-containing aromatic heterocyclic ligand, among others. It is preferable to include a species, and it is preferable to further include a carbon atom substituted with a halogen atom in the organic ligand of these combinations.

Examples of the β-diketone ligand include β-diketone ligands represented by the following general formula (4).

In Q ¹ and Q ² in the general formula (4), the hydrocarbon group includes an aromatic hydrocarbon group, an aliphatic hydrocarbon group, and a combination thereof, and the aliphatic hydrocarbon group is saturated, And unsaturated, linear, branched or cyclic aliphatic hydrocarbon groups.
The aromatic hydrocarbon group includes an aromatic hydrocarbon group having 6 to 22 carbon atoms, and further includes an aromatic hydrocarbon group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group, Examples include biphenyl group, phenanthryl group, dibenzo [c, g] phenanthryl group and the like.
Further, among the aliphatic hydrocarbon groups, as a saturated linear, branched or cyclic aliphatic hydrocarbon group, a saturated linear, branched or cyclic aliphatic hydrocarbon having 1 to 20 carbon atoms And a saturated linear, branched or cyclic aliphatic hydrocarbon group having 1 to 10 carbon atoms. As such a saturated linear, branched or cyclic aliphatic hydrocarbon group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, isopropyl group, tert-butyl group And alkyl groups such as 2-ethylhexyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group and cycloalkyl groups.
Among the aliphatic hydrocarbon groups, the unsaturated linear, branched or cyclic aliphatic hydrocarbon group is an unsaturated linear, branched or cyclic aliphatic group having 2 to 20 carbon atoms. A hydrocarbon group is mentioned, C2-C10 unsaturated linear, branched or cyclic aliphatic hydrocarbon group is mentioned. Examples of such unsaturated linear, branched or cyclic aliphatic hydrocarbon groups include vinyl, allyl, butenyl, pentenyl, hexenyl, octenyl, decenyl and isopropenyl groups. Examples thereof include isobutenyl group, isopentenyl group, 2-ethylhexenyl group, cyclopentenyl group, cyclohexenyl group, ethynyl group, propynyl group, alkenyl group such as butynyl group, cycloalkenyl group, and alkynyl group.
Examples of combinations of aromatic hydrocarbon groups and aliphatic hydrocarbon groups include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and biphenylmethyl group.

In Q ¹ and Q ² , the aromatic heterocyclic group includes at least one hetero atom selected from O (oxygen atom), S (sulfur atom), N (nitrogen atom), and the number of ring carbon atoms 2 or more and 20 or less aromatic heterocyclic groups are mentioned, and further, an aromatic heterocyclic group having 2 to 10 ring carbon atoms is mentioned, and further 4 to 7 membered aromatic heterocyclic groups are mentioned. Be As such an aromatic heterocyclic group, a pyridyl group, a thienyl group, a furyl group, a pyrazolyl group, an imidazolyl group, a benzofuranyl group, a quinolyl group etc. are mentioned, for example.

The said hydrocarbon group and the said aromatic heterocyclic group are a deuterium atom, a halogen atom (F, Cl, Br and I) as needed, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group It may have a substituent such as a phosphonic acid group, a diazo group and a mercapto group. The hydrocarbon group and the aromatic heterocyclic group are, for example, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, an alkylcarbonyl group having 1 to 10 carbon atoms, and the like. May have a substituent of
Furthermore, the aromatic hydrocarbon group and the aromatic heterocyclic group may be substituted by an alkyl group having 10 to 10 carbon atoms or a halogenated alkyl group having 1 to 10 carbon atoms.

Among them, when the compound has a halogen atom as a substituent and has a C—X (X is a halogen atom: F, Cl, Br, and I) bond, it has a low vibration skeleton, and thus includes the structure It is preferable from the viewpoint of functioning so as not to cause vibrational deactivation of the energy received by the rare earth metal, improving the luminous efficiency and improving the luminous intensity.

As Q ¹ and Q ² , each independently, among others, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a perhalogenated aliphatic hydrocarbon group having 1 to 20 carbon atoms, and 6 to 22 carbon atoms Aromatic hydrocarbon group, perhalogenated aromatic hydrocarbon group having 6 to 22 carbon atoms, aromatic heterocyclic group having 2 to 10 ring carbon atoms, and per halogen having 2 to 10 ring carbon atoms Or less selected from the group consisting of halogenated aromatic heterocyclic groups, preferably having 3 to 6 carbon atoms and an aliphatic hydrocarbon group, and having 1 to 20 carbon atoms a perhalogenated aliphatic hydrocarbon group It is preferably at least one selected from the group consisting of an aromatic hydrocarbon group having 6 to 22 carbon atoms and an aromatic heterocyclic group having 2 to 10 ring carbon atoms.

Z in the general formula (4) may be a hydrogen atom H or a deuterium atom D, but is preferably a hydrogen atom H. A deuterated agent is allowed to act on a rare earth metal complex in which Z is H, thereby performing a deuterium substitution reaction to obtain a deuterated complex (a complex in which Z is a deuterium atom D).
Such deuterating agents include, for example, protic compounds containing deuterium, specifically deuterated water; deuterated alcohols such as deuterated methanol and deuterated ethanol; Including alkali and so on. Basic agents and additives such as trimethylamine and triethylamine may be added to accelerate the deuterium substitution reaction.

Examples of the β-diketone ligand include hexafluoroacetylacetone, dibenzoylmethane, 2,2,6,6-tetramethyl-3,5-heptanedione, 4,4,4-trifluoro-1- (2 -Thienyl) -1,3-butanedione, 4,4,4-trifluoro-1- (2-furanyl) -1,3-butanedione, 4,4,4-trifluoro-1- (3-pyridyl)- 1,3-butanedione, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, 4,4,4-trifluoro-1- {5- (2-methylthienyl)}-1,3 -Butanedione, 4,4,4-trifluoro-1- (2-naphthyl) -1,3-butanedione, and 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro- Β-di such as 3,5-octanedione The ligand etc. which are derived from a ketone are mentioned.

Examples of carboxylic acid ligands include ligands having a carboxylate group (—COO ⁻ ), and examples thereof include a formic acid (formato) ligand, an acetic acid (acetato) ligand, and a propionic acid (propionato) coordination. , Citric acid ligand, salicylic acid ligand, terephthalic acid ligand, isophthalic acid ligand, 2-hydroxyterephthalic acid ligand, 1,4-naphthalenedicarboxylic acid ligand, trimesic acid ligand And 1,3,5-tris (4-carboxyphenyl) benzene ligand, and biphenyl-3,3 ', 5,5'-tetracarboxylic acid ligand.

As a phosphine oxide ligand, the phosphine oxide ligand represented by following General formula (1) is preferable.

(In the general formulas (2a) to (2c), R ¹ is each independently a monovalent substituent, X is a sulfur atom or an oxygen atom, and R ² is a hydrogen atom or a hydrocarbon group, m is from 0, if .R ¹ R ¹ is an integer from possible sites substitution in ring linked there are multiple, may be R ¹ is each the same or different.)
In the general formula (1), E is a hydrogen atom or a phosphine oxide group represented by the following general formula (3).

Ar ¹ and Ar ² in the general formula (1) and Ar ⁴ and Ar ⁵ in the general formula (3) are each independently a monovalent aromatic group which may have a substituent .
The aromatic group includes an aromatic hydrocarbon group and an aromatic heterocyclic group. The aromatic hydrocarbon group and the aromatic heterocyclic group here are the same as the aromatic hydrocarbon group and the aromatic heterocyclic group in Q ¹ and Q ² represented by the general formula (4), and good.
Specific examples of the aromatic group of Ar ¹ and Ar ² in the general formula (1) and Ar ⁴ and Ar ^{5 in} the general formula (3) include a phenyl group, a naphthyl group, a biphenyl group and a phenanthryl group. And dibenzo [c, g] phenanthryl group, pyridyl group, thienyl group and the like.
Among the aromatic groups of Ar ¹ and Ar ² in the general formula (1) and Ar ⁴ and Ar ^{5 in} the general formula (3), among them, a phenyl group, a pyridyl group or a thienyl group is preferable, and particularly phenyl Groups are mentioned as being preferred.

Ar ¹ and Ar ² in the general formula (1), and a substituent which Ar ⁴ and Ar ⁵ in the general formula (3) may have, and a monovalent substituent as R ¹ are Examples thereof include a hydrocarbon group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group and the like.

R ² in the general formula (2c) is a hydrogen atom or a hydrocarbon group, and examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and these hydrocarbon groups are It may be the same as the hydrocarbon group in Q ¹ and Q ² represented by the general formula (4). Among them, the hydrocarbon group of R ^{2 in} the general formula (2c) is preferably at least one selected from the group consisting of a phenyl group and an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

In the general formulas (2a), (2b) and (2c), m is an integer from 0 to a substitutable site in the ring to which R ¹ is bonded, and is an integer of 0 or more and 2 or less, among others Is preferable, and 0 is more preferable.

In the general formula (1), n is preferably 1 or 2, and when Ar ³ is a divalent group represented by the general formula (2c), n is preferably 1.
In the general formula (1), E is a hydrogen atom or a phosphine oxide group represented by the general formula (3). In the general formula (1), when E is a phosphine oxide group represented by the general formula (3), the phosphine oxide ligand represented by the general formula (1) is a bidentate ligand. The phosphine oxide ligand may form a rare earth complex including a crosslinked structure formed by coordinating to the two rare earth ions. The rare earth complex containing the crosslinked structure may be hereinafter referred to as a complex polymer.

As a nitrogen-containing aromatic heterocyclic compound which comprises a nitrogen-containing aromatic heterocyclic ligand, a ring assembly compound and a condensed ring compound other than a single ring compound are also contained. The number of atoms constituting the aromatic ring is usually 5 or more and 30 or less, preferably 5 or more and 18 or less, and particularly preferably 6 or more and 10 or less from the viewpoint of easy availability and excellent performance.

Examples of the nitrogen-containing aromatic heterocyclic compound include pyridine, 2-methylpyridine, 2,4,6-trimethylpyridine, 4-dimethylaminopyridine, 2,6-lutidine, pyrimidine, pyridazine, pyrazine, oxazole, and the like. Isoxazole, thiazole, isothiazole, imidazole, 1,2-dimethylimidazole, 3- (dimethylamino) propylimidazole, pyrazole, furazan, pyrazine, quinoline, isoquinoline, purine, 1H-indazole, quinazoline, cinnoline, quinoxaline, phthalazine, Pteridine, phenanthridine, 2,6-di-t-butylpyridine, 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-dimethyl-2,2'- Bipyridyl, 5,5'-dimethyl-2,2'-bipi Lysyl, 6,6'-t-butyl-2,2'-dipyridyl, 4,4'-diphenyl-2,2'-bipyridyl, 1,10-phenanthroline, 2,7-dimethyl-1,10-phenanthroline, Examples include 5,6-dimethyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline and the like. Among the above-mentioned nitrogen-containing aromatic heterocyclic compounds, for example, 1,10-phenanthroline, 2-2′-bipyridyl, 2-2′-6,2 ”-terpyridyl, 2,7-dimethyl-1,10 -Phenanthrolines and pyridines to be bidentate ligands such as -phenanthroline, 5,6-dimethyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline and 2- (2-pyridyl) benzimidazole Is preferably used.

The rare earth complex includes a phosphine oxide bidentate ligand, and the phosphine oxide bidentate ligand includes a cross-linked structure formed by coordinating to two rare earth ions; It is preferable from the point that the strength is improved.
Above all, a phosphine oxide bidentate coordination in which the phosphine oxide bidentate ligand is represented by the general formula (1) and E in the general formula (1) is a phosphine oxide group represented by the general formula (3) In the case of a child, it is more preferable from the viewpoint of being excellent in light resistance and also in solvent resistance. Conventional rare earth complexes with high luminescence intensity are easily soluble in solvents, so they have poor solvent resistance when made into ink compositions and printed matter, and medical management used in sites using alcohol and organic solvents such as medical sites There is a problem that it is not suitable for providing security to labels and the like. Furthermore, security printed matter is required to prevent falsification using a solvent, and there is a problem that the conventional rare earth complex is not suitable also from the viewpoint of falsification prevention. On the other hand, a rare earth complex containing a phosphine oxide bidentate ligand which is a phosphine oxide group represented by the general formula (1) and E in the general formula (1) is represented by the general formula (3) is methanol And an ink composition containing a rare earth complex containing the bidentate phosphine oxide ligand because it is insoluble in an alcohol such as ethanol, or an organic solvent such as acetone, ethyl acetate, hexane, or dichloromethane; The solvent resistance is high, and it can be used for security application used in the field using an organic solvent, and furthermore, it is possible to prevent the falsification using the solvent.

As at least one of the preferred rare earth complexes from the viewpoint of excellent emission intensity, for example, rare earth complexes having a repeating unit represented by the following general formula (5) and rare earth complexes represented by the following general formula (6) There is at least one type. Above all, when the rare earth complex having a repeating unit represented by the following general formula (5) is contained, a printed matter excellent in heat resistance, light resistance and solvent resistance can be produced.

(In the general formula (5), Ln ³⁺ is a group consisting of Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Yb ³⁺ , Nd ³⁺ , Nd ³⁺ , Er ³⁺ , Pr ³⁺ , Ho ³⁺ , Tm ³⁺ , Dy ³⁺ , Ce ³⁺ , and Gd ³⁺ Ar ¹ , Ar ² and Ar ³ are the same as in the above general formula (1), and Ar ⁴ and Ar ⁵ are the same as the above general formula (3), Q ¹ , Q ² and Z are the same as in the above general formula (4).)

(In the general formula (6), Ln ³⁺ is a group consisting of Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Yb ³⁺ , Nd ³⁺ , Nd ³⁺ , Er ³⁺ , Pr ³⁺ , Ho ³⁺ , Tm ³⁺ , Dy ³⁺ , Ce ³⁺ , and Gd ³⁺ Ar ¹ , Ar ² and Ar ³ are the same as in the above general formula (1), and Q ¹ , Q ² and Z are the same as those in the above general formula (4) N1 is an integer of 1 or more and 5 or less, and n2 is an integer of 1 or more and 4 or less.)

In the above general formula (6), n1 is preferably 1 or 2, n2 is preferably 2, 3 or 4, and n1 is 2 and n2 is 3 from the viewpoint of improving the emission intensity. Among them, preferred is one.

The rare earth complex is prepared, for example, by a method of stirring a rare earth metal compound which is a raw material of a rare earth ion and a compound to be a ligand in a solvent which can dissolve or disperse them, if necessary, in the presence of a catalyst. It can be synthesized. As the solvent, a solvent suitable for the compound to be the rare earth metal compound and the ligand may be mixed and used, and for example, a mixed solvent of dichloromethane and methanol can be applied. As a catalyst, for example, trimethylamine, lithium hydroxide and the like can be added, if necessary.

<Long-lasting light emitting material>
As long-lasting light emitting materials, for example, SrAl ₂ O ₄ : Eu, Dy (yellowish green), Sr ₄ Al ₁₄ O ₂₅ : Eu, Dy (blue-green), and CaAl ₂ O ₄ : Eu, Nd (purple-blue) ), ZnS: Cu, Mn, Co (yellow orange), ZnS: Cu (yellow green), Y ₂ O ₂ S: Eu, Mg, Ti (red), Sr ₂ MgSi ₂ O ₈ : Eu, Dy (blue) , Sr ₂ MgSiO ₇ : Eu, Dy (blue), SrAl ₃ O ₅ (OH): Eu, Dy (blue-green), ZnGa ₂ O ₄ : Mn (green), Y ₂ O ₂ S: Eu, Mg, Ti (Red), GdO ₂ S: Eu, Mg, Ti (red) and the like.

Among the above-mentioned materials, those containing an alkaline earth metal aluminate are preferable from the viewpoint of easy availability and high light resistance and afterglow luminance.

Among them, one obtained by adding two or more kinds of rare earth metals to an alkaline earth metal aluminate is a trapping center of one of the rare earth metals, and after trapping electrons or holes generated by light irradiation, Can move to the emission center of different rare earth metal ions to emit light, so it is easy to secure a predetermined time until the emission intensity saturates, and also ensure a long decay time even after the excitation light irradiation is stopped. It is preferable because it is easy to do.

It is preferable that the rare earth complex and the long afterglow light emitting material be blended in a combination in which the emission color when irradiated with a predetermined excitation light is different. More preferably, the absolute value of the difference between the wavelength (λ1) at which the emission intensity of the rare earth complex is maximum and the wavelength (λ2) at which the emission intensity of the long afterglow material is maximum is preferably 30 nm or more, more preferably Is preferably 50 nm or more.

Specifically, SrAl ₂ O ₄ : Eu, Dy (yellowish green), Sr ₄ Al ₁₄ O ₂₅ : Eu, Dy (blue-green), CaAl ₂ O ₄ : Eu, Nd (purple) as a long decay light emitting material Blue), Sr ₂ MgSi ₂ O ₈ : Eu, Dy (blue), Sr ₂ MgSiO ₇ : Eu, Dy (blue), SrAl ₃ O ₅ (OH): Eu, Dy (blue-green), and ZnGa ₂ O ₄ When one or more selected from the group consisting of Mn (green) is used, one or more rare earth ions selected from the group consisting of Eu ³⁺ , Sm ³⁺ , Pr ³⁺ , and Ho ³ are used as the rare earth complex Is preferred.
In addition, as a long decay light emitting material, ZnS: Cu, Mn, Co (yellow orange), Y ₂ O ₂ S: Eu, Mg, Ti (red) and GdO ₂ S: Eu, Mg, Ti (red) When one or more selected from the group is used, a rare earth complex is selected from the group consisting of Tb ³⁺ , Er ³⁺ , Tm ³⁺ , Dy ³⁺ , Yb ³⁺ , Nd ³⁺ , Ce ³⁺ , and Gd ³⁺ It is preferable to use the above.

<Other ingredients>
The ink composition may further contain other components as needed, as long as the effects of the present disclosure are not impaired.
As other components, for example, known adjuvants used in inks other than vehicles, such as dispersants, crosslinking agents, drying accelerators, polymerization inhibitors, waxes, extender pigments, coloring agents, drying inhibitors And antioxidants, surface-adjusting agents, anti-set-off agents, antifoaming agents, surfactants, and the like.

(Vehicle)
The vehicle is a medium having a film forming ability when the rare earth complex is dispersed and applied or printed. The vehicles used in the present disclosure may include known vehicle components used in the ink, such as resins, solvents, photocurable components, and the like.

As the resin contained in the vehicle, known resins can be appropriately selected and used. For example, known resins used in ink may be used, and resins contained in oil-based ink or resins contained in UV ink may be used.
The resin may be a natural or synthetic resin and may be a homopolymer or copolymer. In order to ensure the viscosity of the oil-based ink, the resin is preferably solid. Examples of natural resins include rosin, agate, shellac, and gylsonite.
As the synthetic resin, for example, rosin, phenol resin, modified alkyd resin, polyester resin, petroleum resin, maleic acid resin such as rosin modified maleic resin, cyclized rubber, acrylic resin, one-component urethane resin, two-component urethane And resins and other synthetic resins.
In the case of using an aqueous ink, it may contain, for example, a water-soluble resin, a colloidal dispersion resin, an emulsion resin, and the like.
The resins listed above can be used alone or in combination of two or more.

As the solvent contained in the vehicle, known solvents can be appropriately selected and used. Examples of the solvent include organic solvents, drying oils, semi-drying oils, mineral oils, water and the like.

As a photocurable component contained in a vehicle, a well-known photocurable component can be selected suitably and can be used. The photocurable component includes a monomer, an oligomer, a photopolymerization initiator and the like.
As a monomer, the compound which has the ethylenically unsaturated bond conventionally used for photopolymerization is mentioned. Moreover, an oligomer is obtained by oligomerizing the compound which has an ethylenically unsaturated bond.
Examples of the compound having an ethylenically unsaturated bond include (meth) acrylic acid compounds; maleic acid compounds; urethane compounds, epoxy compounds, polyester compounds, polyol compounds, vegetable oil compounds, etc. The compound etc. which have a heavy bond are mentioned.
The photopolymerization initiator is, for example, a compound which generates a radical such as active oxygen by ultraviolet irradiation. As the photopolymerization initiator, known photopolymerization initiators used for printing may be appropriately selected and contained.

<Composition ratio of each component in the ink composition>
In the ink composition of the present disclosure, the content ratio of the total of the specific rare earth complex and the long afterglow light emitting material to the total solid content of the ink composition is preferably 1% by mass or more from the viewpoint of emission intensity And 5 mass% or more is more preferable. In addition, in this indication, solid content means components other than a solvent.
Further, the ratio of the rare earth complex to the total 100 parts by mass of the rare earth complex and the long afterglow light emitting material contained in the ink composition of the present disclosure is appropriately selected according to the combination of the rare earth complex and the long afterglow light emitting material Although it is not particularly limited, it is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 90 parts by mass or less, from the viewpoint that the color change tends to be large. It is more preferable that it is less than 1 part.
When the ink composition of the present disclosure contains the above-mentioned other components, the ratio of the solid content derived from the above-mentioned other components to the total solid content of the ink composition is 99% by mass or less Is preferable, and 95% by mass or less is more preferable.
When the ink composition of the present disclosure contains a solvent, the ratio of the solid content to the total amount of the ink composition containing the solvent is appropriately adjusted according to the printing method, and is not particularly limited. Therefore, the content is preferably 5% by mass to 80% by mass, and more preferably 10% by mass to 60% by mass.

The method for producing the ink composition of the present disclosure is not particularly limited as long as the ink composition of the present disclosure described above can be obtained, and the other components such as the rare earth complex, the long afterglow light emitting material and the vehicle It can be produced by mixing and dispersing in any order. The mixing and dispersion of the respective components can be carried out by a mixer such as a single-screw mixer and a twin-screw mixer, or an ink mill such as a three-roller mill, a bead mill, a ball mill, a sand grinder and an attritor.

According to the ink composition of the present disclosure described above, by using the above-described rare earth complex in combination with the above-described long decay light emitting material, high emission intensity can be obtained by irradiation with excitation light. In addition, since a large color change can be obtained during or after irradiation with excitation light, it is suitably used for authenticity determination applications, forgery prevention applications, and various security applications.

[Printed matter]
The printed matter according to the embodiment of the present disclosure is a printed matter having an ink layer containing a solidified product of the ink composition according to the embodiment of the present disclosure.
FIG. 1 is a schematic cross-sectional view showing an example of a printed matter according to the present disclosure. The printed matter 1 has the ink layer 11 on one side of the substrate 10. The ink layer 11 is a layer containing a solidified product of the ink composition of the embodiment of the present disclosure, and is formed using the ink composition of the embodiment of the present disclosure.

The printed matter 1 according to the present disclosure may have one or more ink layers 11. When a plurality of ink layers 11 are provided on the substrate 10, the composition or the like of the ink composition forming each ink layer may be the same or different. The ink layer 11 can have an arbitrary pattern.

In addition, the printed matter of the present disclosure has at least the ink layer 11 and, if necessary, a substrate for supporting the ink layer 11 and other layers as long as the effects of the present disclosure are not impaired. It may be done.

<Ink layer>
The ink layer 11 of the printed matter 1 of the present disclosure is an ink layer containing a solidified product of the ink composition of the present disclosure, that is, an ink layer formed using the ink composition of the present disclosure.
The ink composition of the present disclosure is as described above, and thus the description thereof is omitted.
In the present disclosure, the solidified material refers to a material solidified with or without a chemical reaction. Examples of the solidified product include a cured product cured by a curing reaction, a product solidified by drying, and a product solidified by cooling of a thermoplastic resin.

The ink layer can be formed, for example, by applying the ink composition of the present disclosure to a substrate serving as a support and solidifying the ink composition.
The coating method may be a known coating method, and is not particularly limited. For example, flexographic printing, letterpress printing, offset printing, intaglio printing, gravure printing, screen printing, or inkjet printing, or the like can be used. Coating methods such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, etc.
Among these printing methods, silk screen printing, gravure printing, intaglio printing, or offset printing is preferable in order to prevent forgery of printed matter.

The method for solidifying the ink composition is appropriately selected according to the components contained in the ink composition, and is not particularly limited. For example, when the ink composition contains a solvent, the solvent is removed by drying. A method of removing, a method of curing the photocurable component by light irradiation when the ink composition contains a photocurable component, a heating method when the ink composition contains a thermosetting component The method of hardening a thermosetting component, the method of solidifying a molten resin by cooling when the said ink composition contains a thermoplastic resin, the method which combined these methods, etc. are mentioned.
The ink layer may be formed on the entire surface of one side or both sides of the substrate, or may be formed in a pattern.

The fact that the ink layer contains a solidified product of the ink composition of the present disclosure can be confirmed by collecting and analyzing the material from the ink layer. As an analysis method, for example, mass spectrometry such as ESI-Mass, NMR, IR, ICP emission analysis, atomic absorption analysis, X-ray fluorescence analysis, X-ray absorption fine structure analysis (XAFS), and a combination method thereof are applied. can do. The analysis of the rare earth metal can be performed, for example, using a multi-type ICP emission analyzer ICPE-9000 manufactured by Shimadzu Corporation.

<Base material>
Examples of the substrate include high quality paper, art paper, coated paper, cast coated paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internally added paper, cellulose fiber paper, etc., polyolefin ( Plastic sheets of various synthetic resins such as polyethylene, polypropylene, etc., polystyrene, polycarbonate, polyethylene terephthalate, polyvinyl chloride and polymethacrylate, and white opaque films formed by adding white pigments and fillers to these synthetic resins, Or the film (what is called synthetic paper) etc. which have a micro space | gap (micro void) inside a base material etc. are mentioned. The substrate may not necessarily be in the form of a film or sheet, and may be a resin molded product having a three-dimensional shape or the like.

<Use of printed matter>
Although the application of the printed matter of the present disclosure is not particularly limited, the printed matter 1 according to the present disclosure can obtain high emission intensity by the irradiation of the excitation light in the ink layer 11, and during and during the irradiation of the excitation light. Since a large color change can be obtained later, various information management can be performed by reading the change in emission color visually or by a detector or the like. In addition, the printed matter 1 according to the present disclosure is high in authenticity judgment and forgery prevention because of the peculiarity of light emission of the ink layer.

Printed materials include, for example, bills, checks, stock certificates, company bonds, securities such as various securities, banknotes, gift certificates, tickets for transportation, tickets for paid facilities and events, tickets for lottery tickets, and public competition tickets. A ticket, a stamp, a card such as a credit card, a passport, an identification card, various commercial printed matter, a poster, etc. may be mentioned.

(Authentication method)
The authenticity determination for the printed material 1 according to the present disclosure can be performed as follows.
After the excitation light irradiation by the excitation light source is performed for a predetermined time on the ink layer 11 containing the solidified material of the ink composition of one embodiment of the present disclosure, the irradiation of the excitation light is stopped, and the irradiation of the excitation light is performed The intensity difference between the emission intensity of the emission due to the rare earth complex and the emission intensity of the emission due to the long afterglow light emitting material after the irradiation stop is measured by a detector such as a fiber optical spectrometer, for example, and the measured value However, it can be judged whether or not it is within the range of the prescribed value.

In addition, when the light emission due to the rare earth complex and the light emission due to the long afterglow light emitting material are both in the visible light region, the color change during the excitation light irradiation and after the irradiation stop is visually observed. Whether or not the color change matches the predetermined color change can be used to determine the authenticity.

The authenticity determination on the printed matter 1 according to the present disclosure can also be performed as follows. That is, the method for determining authenticity according to one embodiment of the present disclosure rubs the ink layer containing the solidified product of the ink composition according to one embodiment of the present disclosure, and the emission color is changed by the frictional heat generated at that time. Is used to determine the authenticity.
For example, when the ink layer 11 is rubbed with, for example, a friction tool having a friction portion while the ink layer 11 containing the solidified material of the ink composition according to one embodiment of the present disclosure is irradiated with excitation light by an excitation light source At the site alone, the frictional heat generated upon friction changes the difference between the light emission intensity of the light emission due to the rare earth complex and the light emission intensity of the light emission due to the long afterglow light emitting material. The intensity difference of the light emission intensity controlled by such heat is measured by the above-mentioned detector, and the authenticity can be determined depending on whether the measured value is within the range of the prescribed value.
Moreover, when the light emission due to the rare earth complex and the light emission due to the long afterglow light emitting material are both in the visible region, the change in the difference in the light emission intensity is visually observed as the color change of the light emission color You can check it with

For example, it contains a solid of an ink composition containing a red light emitter as a rare earth complex and a green long decay light emitting material as a long decay light emitting material, and is yellow at room temperature when irradiated with excitation light (UV light) The surface of the ink layer, which shows the above, is rubbed while being irradiated with excitation light, the frictional heat is instantaneously heated by the frictional heat, and carriers such as electrons and holes trapped in the capture center of the long afterglow light emitting material rapidly The light is released to the center of light emission. Thereby, the ink layer has a green color, and then the ink layer has a red color when the green light of the long afterglow light emitting material disappears due to the energy release accompanying light emission. If this ink layer is further irradiated with excitation light, energy is gradually supplied to the long afterglow light emitting material, so that the long afterglow light emitting material emits light again, and the ink layer exhibits a yellow color. Then, when the excitation light irradiation is stopped, the ink layer exhibits a green afterglow. By visually confirming the color change of the luminescent color described above, the authenticity determination can be performed.
In addition, when the green light by the long afterglow light emitting material disappears and the irradiation of the excitation light is stopped when the ink layer turns red, carriers causing the long afterglow light emitting material to emit light are trapped at capture centers. However, the afterglow after the termination of the excitation light irradiation can not be obtained.

By using the above-described rare earth complex with high emission intensity as the rare earth complex of the ink composition used in such a method of authenticity determination, when the long afterglow light emitting material emits light and then is quenched by heating by friction etc. Light emission from the complex can be obtained at high intensity. For this reason, it is excellent in visibility and has excellent authenticity judgment.

As a tool for rubbing the ink layer, a friction tool having a friction portion that generates frictional heat by rubbing may be used. For example, as the friction portion, for example, one made of an elastic material having low abrasion resistance can be mentioned. For example, a friction portion such as a rubber portion of a commercially available thermochromic writing instrument may be used.

According to the printed matter of the present disclosure described above, in the ink layer, high emission intensity can be obtained by the irradiation of the excitation light, and the change in intensity difference of the emission intensity is large during and after the irradiation with the excitation light. You can get it. Moreover, according to the printed matter of the present disclosure, even after the excitation light irradiation is stopped, the time for confirmation of the light emission intensity can be sufficiently secured. Therefore, the authenticity determination can be performed with high accuracy, and forgery prevention can be improved.

The following IR measurement was performed using FT / IR-4600 manufactured by Nippon Optical Co., Ltd.
The following ¹ H-NMR measurement was performed using ESC 400 (400 MHz) manufactured by JEOL Ltd., and chemical shifts were determined using tetramethylsilane (TMS) as an internal standard.
The following ESI-Mass measurement was performed using Thermo Scientific Scientific's Thermo Scientific Exactive.
In the following elemental analysis, organic trace elemental analysis was performed using CE440 manufactured by Exeter Analytical.

Synthesis Example 1: Synthesis of 1,4-bis (diphenylphosphoryl) biphenyl (dpbp)
A 100 mL three necked flask was flame dried and the inside was replaced with argon gas. The three-necked flask was charged with 1.9 g (6.0 mmol) of 4,4′-dibromobiphenyl and 30 mL of tetrahydrofuran (THF) and cooled to about −80 ° C. with liquid nitrogen / ethanol. To this solution was slowly added, via syringe, 9.3 mL (15 mmol) of a 1.6 M n-butyllithium hexane solution. The addition took about 15 minutes, during which a yellow precipitate formed. The solution was stirred at −10 ° C. for 3 hours. Next, the solution was cooled again to −80 ° C., 2.7 mL (15 mmol) of dichlorophenyl phosphide was added dropwise, and gradually returned to room temperature while stirring for 14 hours. After that, the reaction was stopped and extraction was performed with ethyl acetate. The resulting solution was washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated by an evaporator. The resulting crude product was purified by washing with acetone and ethanol several times to obtain a white powder.
Next, the white powder obtained above and about 40 mL of dichloromethane were placed in a flask, this solution was cooled to 0 ° C., and 30% aqueous hydrogen peroxide (about 5 mL) was added thereto. The mixture was stirred for 2 hours. The product was extracted with dichloromethane, and the extract was washed three times with saturated brine and dried over anhydrous magnesium sulfate. Thereafter, the solvent was distilled off with an evaporator to obtain a white powder. The white powder was recrystallized with dichloromethane to give white crystals of 1,4-bis (diphenylphosphoryl) biphenyl. The analytical results of the white crystals are as follows.

IR (ATR): 1119 (st, P = O) cm ^-1 .
¹ H-NMR (400 MHz, CDCl ₃ , 25 ° C.) δ 7.65-7.80 (m, 16 H; P-C ₆ H ₅ , C ₆ H ₄ ), 7.43-7. 60 (m, 12 H; _{_{_{_{P-C 6 H 5, C}}}} 6 H 4) ppm.
ESI-Mass (m / z) = 555.2 [M + H] ^< +>.
Elemental _analysis: (Calculated for _{_{_{C 36 H 28 O 2 P 2}}} ): C, 77.97; H, 5.09%, ( Found): C, 77.49; H, 5.20%

Synthesis Example 2: Synthesis of Eu Complex Polymer (Compound 1)
Tris (hexafluoroacetylacetonato (hfa)) europium is prepared by mixing europium acetate, which is a raw material of Eu (III) ion, and 1,1,1,5,5-hexafluoro-2,4-pentanedione (III) Dihydrate was synthesized.
Then, 1 equivalent of this tris (hexafluoroacetylacetonato) europium (III) dihydrate and 1 equivalent of 1,4-bis (diphenylphosphoryl) biphenyl obtained in the above-mentioned Synthesis Example 1 are added to methanol (20 mL). It dissolved. The solution was refluxed with stirring for 8 hours. Thereafter, the white powder precipitated in the reaction solution is separated by filtration, washed with methanol multiple times, and then dried under reduced pressure to obtain an Eu complex polymer represented by the following chemical formula [Eu (hfa) ₃ (dpbp)] _n ( Compound 1) was obtained.
In addition, it was confirmed by IR and elemental analysis that the obtained product is an Eu complex polymer (compound 1) represented by the following chemical formula. The analysis results are shown below.

IR (ATR): 1652 (st, C = O), 1250 (st, C-F), 1122 (st, P = O) cm ^-1 ,
ESI-Mass (m / z) = 1675.2 [Eu (hfa) ₂ (dpbp) ₂ ] ⁺ , 1905.2 [[Eu (hfa) ₃ (dpbp) ₂ ] + Na] ⁺
Elemental analysis: (Calculated value of [C ₅₁ H ₃₁ EuF ₁₈ O ₈ P ₂ ] _n ), C, 46.14; H, 2.35% (actual value), C, 46. 10; H, 2. 17%

Synthesis Example 3 Synthesis of Eu Complex (Compound 2)
A methanol solution containing tris (hexafluoroacetylacetonato (hfa)) europium (III) and triphenylphosphine oxide (TPPO) synthesized by the same method as in Synthesis Example 2 is prepared, and the solution is refluxed while refluxing. Stir for 12 hours. Thereafter, methanol was removed by evaporation under reduced pressure to obtain a white powder. The powder was washed with toluene and unreacted tris (hexafluoroacetylacetonato) europium (III) was removed by suction filtration, and then the toluene was evaporated under reduced pressure. The resulting product is washed with hexane to obtain a powder, which is further purified by recrystallization with a mixed solvent of toluene and hexane to obtain an Eu complex (compound 2) represented by the following chemical formula The
In addition, it was confirmed by IR and elemental analysis that the obtained product is an Eu complex [Eu (hfa) ₃ (TPPO) ₂ ] (compound 2) represented by the following chemical formula. The analysis results are shown below.

IR (ATR): 1652 (st, C = O), 1251 (st, C-F), 1121 (st, P = O) cm ^-1 ,
ESI-Mass (m / z) = 1123.1 [Eu (hfa) ₂ (TPPO) ₂ ] ⁺ , 1353.1 [[Eu (hfa) ₃ (TPPO) ₂ ] + Na] ⁺
Elemental analysis: ([C ₅₁ H ₃₃ EuF ₁₈ O ₈ P ₂ calculated value), C, 46.07; H, 2.50%, (found value), C, 46. 10; H, 2.34%

Example 1
(1) Production of Ink Composition As a red light emitter, 10 parts by weight of the specific rare earth complex (Compound 1 of Synthesis Example 1) and a long decay light emitting material 1 (GLL-300FF, Nemoto) as an afterglow material Luminescent powder mixture 1 was obtained by mixing 90 parts by weight of Lumimaleial, SrAl ₂ O ₄ : Eu, Dy). In addition, when the afterglow time after excitation light stop was measured with the following evaluation method, the said long-afterglow light-emitting material 1 had an afterglow time of 5 seconds or more, and was a thing of 1 second or more.
The ink composition is prepared by kneading 30 parts by weight of the luminous powder mixture 1 and 70 parts by weight of a UV-curable vehicle (trade name: UV BF SGA medium, manufactured by DIC Graphics) as a vehicle with a three-roll mill. I got one.
(2) Production of Printed Matter The obtained ink composition 1 is coated on a printing paper with a bar coater and then photocured by ultraviolet irradiation to have an ink layer containing a solidified product of the ink composition. Example 1 I got the printed matter of.

(Example 2)
A mixture of 30 parts by weight of the specific rare earth complex (Compound 1 of Synthesis Example 1) as a red light emitter and 70 parts by weight of a long decay light emitting material 1 as an afterglow material to obtain a light emitting powder mixture 2 I got An ink composition 2 was obtained in the same manner as in Example 1, except that the luminous powder mixture 1 was replaced with the luminous powder mixture 2.
Printed matter was obtained in the same manner as Example 1 using the obtained ink composition 2.

(Example 3)
A light emitting powder mixture 3 was obtained by mixing 50 parts by weight of the specific rare earth complex (Compound 1 of Synthesis Example 1) and 50 parts by weight of the long decay light emitting material 1 as a red light emitting body. An ink composition 3 was obtained in the same manner as Example 1, except that the luminous powder mixture 1 was replaced with the luminous powder mixture 3.
Printed matter was obtained using the obtained ink composition 3 in the same manner as Example 1.

(Example 4)
A light emitting powder mixture 4 was obtained by mixing 70 parts by weight of the specific rare earth complex (Compound 1 of Synthesis Example 1) and 30 parts by weight of the long decay light emitting material 1 as a red light emitter. An ink composition 4 was obtained in the same manner as Example 1, except that the luminous powder mixture 1 was replaced with the luminous powder mixture 4.
Printed matter was obtained in the same manner as Example 1 using the obtained ink composition 4.

(Example 5)
A light emitting powder is prepared in the same manner as in Example 1 except that the specific rare earth complex (Compound 1 of Synthesis Example 1) is replaced by the specific rare earth complex (Compound 2 of Synthesis Example 2) as a red light emitter. Mixture 5 was obtained. An ink composition 5 was obtained in the same manner as in Example 1, except that the luminous powder mixture 1 was replaced with the luminous powder mixture 5.
Printed matter was obtained using the obtained ink composition 5 in the same manner as in Example 1.

(Example 6)
A light emitting powder is prepared in the same manner as in Example 2 except that the specific rare earth complex (Compound 1 of Synthesis Example 1) is replaced with the specific rare earth complex (Compound 2 of Synthesis Example 2) as a red light emitter. Mixture 6 was obtained. An ink composition 6 was obtained in the same manner as in Example 2, except that the luminous powder mixture 2 was replaced with the luminous powder mixture 6.
Printed matter was obtained using the obtained ink composition 6 in the same manner as in Example 1.

(Example 7)
A light emitting powder is prepared in the same manner as in Example 3 except that the specific rare earth complex (Compound 1 of Synthesis Example 1) is replaced with the specific rare earth complex (Compound 2 of Synthesis Example 2) as a red light emitter. Mixture 7 was obtained. An ink composition 7 was obtained in the same manner as in Example 3, except that the luminous powder mixture 3 was replaced with the luminous powder mixture 7.
Printed matter was obtained using the obtained ink composition 7 in the same manner as in Example 1.

(Example 8)
A light emitting powder is prepared in the same manner as in Example 4 except that the specific rare earth complex (Compound 1 of Synthesis Example 1) is replaced with the specific rare earth complex (Compound 2 of Synthesis Example 2) as a red light emitter. Mixture 8 was obtained. An ink composition 8 was obtained in the same manner as in Example 4, except that the luminous powder mixture 4 was replaced with the luminous powder mixture 8.
Printed matter was obtained using the obtained ink composition 8 in the same manner as in Example 1.

(Example 9)
As a red light emitter, 1 part by weight of a red light emitting rare earth complex (compound 3 represented by the following chemical formula, Eu (TTA) Phen, manufactured by Tokyo Chemical Industry Co., Ltd.) and 99 parts by weight of long decay light emitting material 1 are mixed A light emitting powder mixture 9 was obtained. An ink composition 9 was obtained in the same manner as Example 1, except that the luminous powder mixture 1 was replaced with the luminous powder mixture 9.
Printed matter was obtained using the obtained ink composition 9 in the same manner as in Example 1.

(Comparative example 1)
A light emitting powder is prepared in the same manner as in Example 2 except that the compound 1 is replaced by a red light emitting inorganic oxide (compound 4, D1124, manufactured by NEMOTRUMI MATERIALS, Y ₂ O ₂ S: Eu) as a red light emitter. Mixture 10 was obtained. An ink composition 10 was obtained in the same manner as Example 2, except that the luminous powder mixture 2 was replaced with the luminous powder mixture 10.
Printed matter was obtained in the same manner as Example 1 using the obtained ink composition 10.

(Comparative example 2)
A light emitting powder mixture 11 was obtained in the same manner as in Example 3, except that the compound 1 was replaced with a red light emitting inorganic oxide (compound 4) as a red light emitting body. An ink composition 11 was obtained in the same manner as in Example 3, except that the luminous powder mixture 3 was replaced with the luminous powder mixture 11.
Printed matter was obtained in the same manner as in Example 1 using the obtained ink composition 11.

(Comparative example 3)
A light emitting powder mixture 12 was obtained in the same manner as in Example 4 except that the compound 1 was replaced with a red light emitting inorganic oxide (compound 4) as a red light emitting material. An ink composition 12 was obtained in the same manner as Example 4, except that the luminous powder mixture 4 was replaced with the luminous powder mixture 12.
Printed matter was obtained in the same manner as Example 1 using the obtained ink composition 12.

(Comparative example 4)
Example 3 is the same as Example 3 except that the long decay light emitting material 1 is replaced by the short decay light emitting material 1 (D1164, manufactured by NEMOTOMI MATERIALS, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn) as a long decay material. In the same manner, a luminescent powder mixture 13 was obtained. In addition, when the said short afterglow light emitting material 1 measured the afterglow time after excitation light stop by the following evaluation method, it was 40 milliseconds or less.
An ink composition 13 was obtained in the same manner as in Example 3, except that the luminous powder mixture 3 was replaced with the luminous powder mixture 13. The obtained ink composition 13 was coated on a printing paper with a bar coater, and then photocured by ultraviolet irradiation to form an ink layer, thereby obtaining a printed matter.

(Comparative example 5)
A light emitting powder mixture 14 was obtained in the same manner as in Example 4, except that the long afterglow light emitting material 1 was replaced by the short afterglow light emitting material 1 as the afterglow material. An ink composition 14 was obtained in the same manner as in Example 4 except that the luminous powder mixture 4 was replaced with the luminous powder mixture 14. The obtained ink composition 14 was coated on a printing paper with a bar coater, and then photocured by ultraviolet irradiation to form an ink layer, thereby obtaining a printed matter.

(Reference example: Red light emission printed matter (reference sample of emission intensity))
An ink composition 15 was prepared in the same manner as in Example 1, except that the luminous powder mixture 1 was replaced by a luminous powder mixture 15 consisting of 100 parts by weight of a red light emitting inorganic oxide (trade name D1124 made by Nemoto Lumimaterial). Obtained. The obtained ink composition 15 was coated on a printing paper with a bar coater, and then photocured by ultraviolet irradiation to form an ink layer, whereby a red light emitting printed matter (reference sample of light emission intensity) was obtained.

(Evaluation)
<Emission spectrum measurement>
About the ink layer formed in each printed matter of Examples 1 to 9 and Comparative Examples 1 to 5, using a small fiber optical spectroscope (USB 2000+, manufactured by Ocean Optics), a handy UV lamp (SLUV-6, manufactured by As One) The emission spectrum in the state excited by irradiating the excitation light (UV light) of wavelength 365nm was measured.
Among them, the emission spectra of each ink layer obtained in Example 2 and Comparative Example 3 are shown in FIGS. 2 to 7 immediately after UV irradiation, 5 seconds after UV irradiation and after UV irradiation is stopped. In each of the graphs shown in FIGS. 2 to 7, the horizontal axis is wavelength (nm) and the vertical axis is relative intensity.

In Example 2, strong red light emission (613 nm) and very weak green light emission (520 nm) are observed immediately after UV irradiation (FIG. 2), and 5 seconds after UV irradiation (FIG. 3) strong red light emission (613 nm) And strong green emission (520 nm) was observed, and after stopping UV irradiation (FIG. 4), only weak green emission (520 nm) was observed.
On the other hand, the emission spectrum of Comparative Example 3 is compared with the emission spectrum of Example 2 immediately after UV irradiation (FIG. 5) and after 5 seconds of UV irradiation (FIG. 6) after stopping UV irradiation (FIG. 7). It was confirmed that the strength was reduced.

<Color change>
The ink layer formed on each of the printed materials of Examples 1 to 9 and Comparative Examples 1 to 5 was irradiated with excitation light of 365 nm using a handy UV lamp SLUV-6 (manufactured by As One), and maintained for 5 seconds, Irradiation was stopped. Immediately after the UV irradiation and 5 seconds after the UV irradiation, the color change of each ink layer after the UV irradiation was stopped was visually observed. In addition, the emission intensity of each ink layer at a point 5 seconds after UV irradiation was visually confirmed. The evaluation results are shown in Table 1.

<Emission intensity>
About the ink layer of the red light emission printed matter (reference sample of luminescence intensity) obtained by the reference example and the ink layer of the printed matter obtained in Examples 1 to 9 and Comparative Examples 1 to 5, a spectrofluorimeter RF-6000 (Shimadzu The emission spectrum was measured by excitation at a wavelength of 365 nm using a manufactured product. From the emission peak area at 390 to 720 nm of the obtained emission spectrum, the emission intensity was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
[Evaluation standard of luminescence intensity]
A: The emission peak area is 200% or more with respect to the emission peak area of the reference sample (red light emission printed matter of reference example) C: the emission peak area with respect to the emission peak area of the reference sample (red light emission printed matter of reference example) Less than 200%

<Afterglow time measurement>
Regarding the powder of long afterglow light emitting material 1 (GLL-300FF, manufactured by NEMOTRUMI MATERIALS) and short afterglow light emitting material 1 (D1164, manufactured by NEMOTRUMI MATERIALS), as shown in “FP-6600, manufactured by JASCO Corporation” Afterglow time was measured using the “phosphorescence lifetime measurement program”. The excitation wavelength is 365 nm, the shutter on the excitation side is closed and excitation light irradiation is stopped at the same time measurement is started, and the time until the emission intensity value becomes 0.01% or less of the maximum emission intensity value immediately after the measurement opening remains It was light time. The detection wavelength was the maximum emission peak wavelength of the emission spectrum of each sample.

<Wavelength at which emission intensity is maximum>
Compound 1: 613 nm
Compound 2: 617 nm
Compound 3: 612 nm
Compound 4: 626 nm
Long decay light emitting material 1: 521 nm
Short afterglow light emitting material 1: 513 nm

In Examples 1 to 9, it is possible to combine the compound 1, the compound 2 or the compound 3 which is a specific rare earth complex of the present disclosure and the long decay light emitting material 1 which is a long decay light emitting material as a red light emitter. The light emission intensity was high, and a color change which can be sufficiently recognized visually was obtained during and after UV irradiation, and an ink layer having excellent visibility could be obtained. This is because the long afterglow light emitting material requires a certain period of time to saturate the light emission intensity, and also has an afterglow time of 1 second or more, and thus the high light emission intensity compound 1, compound as described above By combining with 2 or the compound 3, a large difference in emission intensity can be obtained between a plurality of wavelength regions immediately after UV irradiation, during UV irradiation and after UV irradiation stop, and this emission intensity difference can be obtained during UV irradiation and This is because it becomes possible to visually recognize as a color change after stopping the UV irradiation.
Compound 4 which is a red light emitting inorganic oxide used in Comparative Examples 1 to 3 has a small emission intensity, so that the compounding ratio with the long afterglow light emitting material is such that the light emission color is the same as in Examples 2 to 4 In the case of combination with the above, the light emission intensity was lowered, resulting in poor visibility. Moreover, in Comparative Example 5 and Comparative Example 6, since the afterglow time of the short afterglow light emitting material 1 is as short as less than 1 second, color change of the ink layer may be visually confirmed during and after UV irradiation. It was difficult.

<Confirmation of color change due to frictional heat of luminescent color>
About the ink layer of the printed matter of the obtained Example and comparative example, the color change by the frictional heat in the luminescence state excited by 365 nm was observed using the handy UV lamp (SLUV-6, product made from As One). The frictional heat was generated by rubbing the surface of the ink layer with the rubber part of FRIXION BALL (registered trademark, made by Pilot). Generally, the frictional heat generated by rubbing at the rubber portion is said to be 60 to 80.degree.
As a result, the ink layer of the printed matter of the example becomes dark green immediately after rubbing, then changes to red, and changes to colors immediately after UV irradiation and 5 seconds after UV irradiation when UV irradiation is continued. It was revealed that
The ink layers of the prints of Comparative Examples 1 to 3 also show a color change in which the green color momentarily darkens immediately after rubbing and then changes to red, but compared to the color change when the ink layer of Example is rubbed. And the visibility was low. Incidentally, it has not been known conventionally that color change can be confirmed by rubbing an ink layer containing an afterglow material and a light emitter.

1 printed matter 10 base material 11 ink layer

Claims

A kind of trivalent rare earth ion selected from the group consisting of Eu3 + , Tb3 + , Sm3 + , Yb3 + , Nd3 + , Er3 + , Pr3 + , Ho3 + , Tm3 + , Dy3 + , Ce3 + , and Gd3 + A rare earth complex comprising at least one organic ligand selected from β-diketone ligands, carboxylic acid ligands, phosphine oxide ligands, and nitrogen-containing aromatic heterocyclic ligands;
An ink composition comprising a long afterglow light emitting material having an afterglow time after the termination of excitation light irradiation which is 1 second or more.
The ink composition according to claim 1, wherein the long afterglow light emitting material contains an alkaline earth metal aluminate.
The ink composition according to claim 1, wherein the rare earth complex contains a phosphine oxide ligand represented by the following general formula (1) as the organic ligand.

[In general formula (1), Ar 1 and Ar 2 are each independently a monovalent aromatic group which may have a substituent. In General Formula (1), Ar 3 is a divalent group represented by the following General Formula (2a), (2b) or (2c), and n is 1 or 2.

(In the general formulas (2a) to (2c), R 1 is each independently a monovalent substituent, X is a sulfur atom or an oxygen atom, and R 2 is a hydrogen atom or a hydrocarbon group, m is from 0, if .R 1 R 1 is an integer from possible sites substitution in ring linked there are multiple, may be R 1 is each the same or different.)
In the general formula (1), E is a hydrogen atom or a phosphine oxide group represented by the following general formula (3).

(In General Formula (3), Ar 4 and Ar 5 are each independently a monovalent aromatic group which may have a substituent.)]
The rare earth complex according to any one of claims 1 to 3, wherein the rare earth complex comprises a phosphine oxide bidentate ligand, and the phosphine oxide bidentate ligand comprises a crosslinked structure formed by coordinating to the two rare earth ions. The ink composition according to any one of the preceding claims.
The ink composition according to any one of claims 1 to 4, wherein the rare earth complex contains a β-diketone ligand represented by the following general formula (4) as the organic ligand.

(In General Formula (4), Q 1 and Q 2 are each independently a hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, Z is a hydrogen atom or a deuterium atom)
The long decay light emitting material contains at least one selected from the group consisting of SrAl 2 O 4 : Eu, Dy, Sr 4 Al 14 O 25 : Eu, Dy, and CaAl 2 O 4 : Eu, Nd. The ink composition according to any one of Items 1 to 5.
A printed matter having an ink layer containing the solidified product of the ink composition according to any one of claims 1 to 6.